MLS's remarkable run of success with its expansion teams will be put to a test when two new teams join.

In mid-March, two more teams are expected to come aboard. Vancouver and Miami head the list, Portland is a possibility, and St. Louis and Ottawa are still in the hunt.

Whichever of those five are chosen will have high benchmarks to attain, particularly with 2009 debutant Seattle projecting average attendances of 25,000 per game.FIRST WAVE (1998). Since it added Miami and Chicago as its first two expansion teams, MLS has got it right more often than not.

It folded the Fusion (along with founding club Tampa Bay) after the 2001 season and losses of about $40 million in Miami, but the Fire won a title in its first year and reached the 2000 and 2003 championship games. Three years ago, it moved into its own facility - Toyota Park - in suburban Bridgeview, Ill. The Fire hosted the 2006 All-Star Game and has averaged 16,490 (2007) and 17,034 (2008) fans in its two full seasons of operation in Bridgeview.GOING WEST (2005). Mexican entrepreneur Jorge Vergara turned up as a possible MLS owner when his club, Guadalajara, played the MLS All-Stars at Home Depot Center in 2003; he wanted to start up his Chivas USA franchise the following year, but agreed to come in a year later.

The other debutant, Real Salt Lake, came as a surprise, yet operator-investor Dave Checketts, formerly president of the NBA Jazz and Knicks, led an aggressive campaign that designed, developed and built a soccer-specific stadium in just four years. Opened last October, Rio Tinto Stadium holds 20,000 and will host this year's All-Star Game as well as a U.S. Hexagonal qualifier in September.

Chivas USA struggled on and off the field during its first season and has since played down its connection to the Mexican club. Chivas USA, which has reached the playoffs the past three seasons, shares HDC with the Galaxy and pays more than $1 million in rent per year to AEG, which also sells its sponsorships and takes a cut of the proceeds.

HEADING NORTH (2007). On the field, Toronto FC has missed the playoffs in its first two seasons yet has led the league in many business parameters. More important, it provided MLS an entry into Canada through Maple Leaf Sports & Entertainment, which also owns the NHL Maple Leafs.

BMO Field regularly sells out for MLS games, and the team is covered extensively in local newspapers and on radio and TV stations. About 2,000 members of its "Red Army" traveled to Columbus last year and so thoroughly out-chanted and out-cheered the three Crew fan clubs that they banded together for subsequent games to form the Nordecke ("North Deck").

TFC officials cut off season-ticket sales at 16,000 last year to give other fans a chance to attend matches, and attend they did: officially, Toronto averaged 20,120 fans last year, second in the league only to the Galaxy's 26,009. Unofficially, TFC leads the league in fans actually attending games.

BACK TO THE BAY AREA (2008). AEG moved the original Quakes, league champions in 2001 and 2003, to Houston after the 2005 season, but MLS retained the team nickname and colors. In 2007, it awarded an expansion franchise to Lewis Wolff and John Fisher, co-owners of the Oakland A's. They melded some team operations with those of the A's, and spent about $3 million to renovate Buck Shaw Stadium on the campus of Santa Clara University.

Buck Shaw, with a capacity of about 10,500, hosts most games. A few major games are staged at the Oakland Coliseum, where the A's play. A stadium (projected capacity: 15,000) is proposed to be built near San Jose International Airport.

(This article originally appeared in the March 2009 issue of Soccer America magazine.)